Speed governing apparatus for injection internal combustion engines



Sept. 21, 1937. A. SCHWEIZER SPEED GOVERNING APPARATUS FOR INJECTION INTERNAL COMBUSTION ENGINES Filed Sept. 1, 1956 Patented sen. 2i, i937 SPEED GOVERNING APPARATUS FOR IN- JEG'ETIQN INTERNAL COBEUS'EIQN EN- GENES Alfred Schweizer, Stuttgart, Germany, assignor to Robert Bosch Aktiengesellschaft, Stuttgart,

Germany Application September 1, 193's, Serial No. 98,950 In Germany September 27, 1935 6 Claims. (or. 123-140) v Figure 2 shows the same parts on another pos- This invention relates to speed-governing apparatus for injection internal combustion engines of the type wherein the amount of fuel injected is controlled by a pneumatic governor operated by the pressure in the engine air supply pipe in which a voluntarily adjustable throttle member is provided. I

An'object of this'inv'ention is to ensure that the governor may operate even when the engine is reversed and when the throttle valve may not be quite tightly closed as otherwise the engine may attain a speed considerably in excess of the idling speed, and one at which the engine can 1 give out an appreciable output. If now for ex- 5 ample a strongly throttled engine running idle should suddenly run in the reverse direction, and the driver in ignorance of this starts the vehicle, the vehicle, in spiteof a safety device against uncontrolled running of the type in which a bypass is provided in the engine air supply pipe and in communication with the governor, which by-pass extends to oppositesides of the throttle valve in said pipe and'is proportioned so that with the throttle. valve closed, the maximum volume of air capable of passing through the by-pass is that volume enabling idle running only of the engine, could unintentionally run backwards and cause damagebefore the engine was again declutchecl andthe vehicle braked. In order to avoid these possibilitiea'by the arrangementaccording. to the present invention a reduction in the speed of a. reverse running internal combustion engine to the-idle running speed, or even r a stopping of the engine, is obtained.

The arrangement of this invention consists in a non-return valve, which during the running in the normal direction of rotation allows a part of the air amount for idle running to enter the space behind the throttle-valve, but which on reverse ,flow impulse in the induction pipe and whenever the engine reverses, closes, wholly or at least for the greater part its previously free.

sible construction, and

Figure 3 shows the same parts in a third example of construction.

In Figure 1, i is the casing of a fuel injection pump of known construction, having a cam-shaft 2 and pump pistons 3, which are rotated about their axis by a toothed rackbar l. According to the degreeof this angular movement, the separate pumps can deliver more or less fuel into.

the cylinders of the internal combustion engine to be governed. A pneumatic governor is built on to the casing i, and its piston 5 can adjust the rackbar 4, and its casing t is connected by a pipe I to the induction-pipe 8 of the engine and at the other side by the opening 6' with the- The free cross-section of the inatmosphere. duction-pipe 8 for the passage of air can be controlled by the throttle-valve 9, which can be adjusted by the driver by means of the rod l0 and the pedal lever it. The throttle-valve 9 oscil lates in a Venturi-tube insert i2 arranged in the induction-pipe 8. I

. In the most contracted part or throat of this Venturi-insert 82 a by-pass divided ofi from the throat passage is arranged, through which a part of the induction air can flow independently of the rocking movement of the throttle-valve 9. The by-pass consists of a symmetrical auxiliary venturi l3, whose long axis'lies parallel to that of the induction-pipe 8, and to the centre of which the pipe 1 leading to the casing 6 of the pneumatic governor is connected, the end of the pipe 7 projecting into the contracted part of the venturi. The ends of the auxiliary Venturi tube l3 do not however extend beyond the cylindrical part of the throat of the Venturi insert i2.

The auxiliary venturi l3 lies with its induction air end within the path of swing of the throttie-valve 9, which is slotted on this side and in the idle running position engages with this slot over the auxiliary Venturi l3, so that its induction opening remains open even when the throttle-valve is closed.

Accordingto Figure 1, a still further passage for a further part of the induced air is provided in the throat of the Venturi insert l2, which passage, according to the invention, is only open during the flowing of the induction air, and automatically closes on the engine running in the reverse direction. In the throttle-valve9 itself a non-return valve is arranged, consisting of a springy flap M, which can close an opening, l5.

This arrangement works in such a way that,

on the ordinary Working direction of rotation of the engine, the air is drawn through the induction pipe 8 in the direction of the arrow A. In the idle running position shown, the induction air will flow through the gap round the throttle-valve 9 and through the non-return valve in the throttle-valve, and further, in this case a suificient current will exist in the by-pass of the auxiliary venturi l3 arranged in the Venturi insert l2, so that through this auxiliary venturi a sumcient degree of vacuum is produced at the end of the pipe I, to operate the pneumatic governor.

On a change in the direction of rotation of the engine, the cylinder charge is forced through the induction-pipe in the direction of the arrow B. The passage through the opening l5 of the closed throttle-valve 9 is now closed by the non-return valve, and the whole charge of the cylinder goes through the symmetrical auxiliary venturi [3, in which it produces the vacuum necessary for operating the pneumatic governor. As the current flowing backwards through the auxiliary venturi l3, owing to the closing of the non-return valve, is at least as great as that during the induction of the air on the normal direction of rotation of the engine, an equally high vacuum can act on the pneumatic governor on the reverse running of the engine, and its piston 5 will-move the controlling rod 4 in such a way as to keep the amount of fuel delivered by the pistons 3 the same as during idle running. This vacuum may also be so strengthened by making the auxiliary venturi I3 in the Venturi insert l2, of suitable dimensions that the pneumatic governor entirely stops the engine in a short time after it starts to run in reverse.

The construction shown in Figure 2 shows a one-winged throttle-valve 9a in the idle running position, this valve itself acting as the non-return valve. The rod Illa of the throttle-valve, when the engine is running idle, strikes on a stop l6, which is held in the position'shown under the pressure of a spring II. When the reverse flow impulse and movement of the cylinder charge in the direction 3" occurs, the throttle-valve is quite closed, while the lever rod Illa moves the stop It into its end-position against the pressure of the spring. On the full closure of the passage through the inductiOn-ninaa current ,is set up in the by-pass l8, provided with a venturi l3a, wh ch is as stron as. or stro er than. the current occurring during the induction of the air, so that in this way an e u y g eat r increased vacuum acts on he pn umatic ov rnor. wh ch causes a reduction in th ermine s ed to the idling speed, or a stop age of the engine.

The part of the a r for idle running wh ch passes beh nd he throttle member on the induction stroke. but whose entrance thereto is prevented on the reverse running of the engine, may also pass through an auxiliary o ening l9 into the induction-pipe 8, and the auxiliary opening situated in front of the throttle-valve 9 may be closed by a flap valve 20. In this arrangement also, which is shown in Figure 3 on the reverse running of the engine, a current will enter the by-pass l8 which is at least as great as or greater than the amount of air entering through the auxiliary opening [9, which enables the engine to continue to run idly or a stopping of the engine on reverse running.

I declare that what I claim is:

1. A speed governing apparatus for injection internal combustion engines comprising an air supply conduit, a voluntarily adjustable throttle valve, a pneumatic governor operated bythe pressure in said conduit and controlling the supply of fuel to said engine, a by-pass in said air supply conduit extending to opposite sides of said throttle valve when closed and in communication with said governor, said by-pass being proportioned so that with the throttle valve closed thevolume of air capable of passing through the by-pass isonly a part of that volume which enables idle running of the engine, and an automatic one-way valve controlling flow in said air supply conduit and thereby influencing flow in said by-pass.

2. A speed governing apparatus for injection internal combustion engines comprising an air supply conduit, a voluntarily adjustable throttle valve, a pneumatic governor operated by the pressure in said conduit and controlling the supply of fuel to said engine, a by-pass in said air supply conduit extending to opposite sides of said throttle valve when closed and in communication with said governor, said throttle valve being provided with means cooperating therewith to form an automatic one-way valve controlling flow in said air supply conduit and thereby influencing flow in said by-pass.

3. A speed governing apparatus for injection internal combustion engines comprising an air supply conduit, a voluntarily adjustable throttle valve, a pneumatic governor operated by the pressure in said conduit and controlling the supply of fuel tosaid engine, a by-pass in said air supply conduit extending to opposite sides of said throttle valve when closed and in communication with said governor, a venturi in said by-pass; said by-pass being proportioned so that with the throttle valve closed the volume of air capable of passing through the by-pass is only a part of that volume which enables idle running of the engine, and an automatic one-way valve controlling flow in said air supply conduit and thereby influencing flow in said by-pass.

4. A speed governing apparatus for injection internal combustion engines comprising an air supply conduit, a venturi in said conduit, a voluntarily adjustable throttle valve in said venturi, a pneumatic governor operated by pressure in said conduit and controlling the supply of fuel to said engine, a by-pass in said air supply conduit extending to opposite sides of said throttle va ve when closed and in commun cation with said governor, a venturi in said by-pass, said by-pass being proportioned so that with the throttle valve closed the volume of air capable of passing through the by-pass is only a art of that volume which enables idle runn ng of the engine, and an automatic one-way valve controll ng flow in said air supply conduit and thereby influencing to opposite sides of said throttle valve when closed and in communication with said governor.

6. A speed governing apparatus for injection internal combustion engines comprising an air supply conduit, a throttle valve, means for volgovernor, and means cooperating with said throttle valve when it approaches the closed positlonpermitting said valve to act as an automatic I one-way valve controlling flow in said air supply conduit. ALFRED SCHWE IZER. 

